Betalactams_Cephalosporins_updated (1) Flashcards
Where were cephalosporins isolated from?
Cephalosporium acremonium in Sardinia
What does cephalosporin inhibit the synthesis of?
Bacterial peptidoglycan
What makes cephalosporins more resistant to penicillinases?
Slightly different nucleus shape
What are examples of beta-lactam antibiotics?
Amoxicillin, Cephalexin, Imipenem, Aztreonam
What type of antibiotic is Amoxicillin?
Penicillin
What type of antibiotic is Cephalexin?
Cephalosporin
What type of antibiotic is Imipenem?
Carbapenem
What type of antibiotic is Aztreonam?
Monobactam
What is the mechanism of action of cephalosporins?
Bind to transpeptidase, disrupting cell wall synthesis
How do cephalosporins exert their bactericidal effect?
Time-dependent, concentration-independent activity
What is the spectrum of activity for Gen1 cephalosporins?
Mostly Gram+, less against Gram-
What infections are early generation oral cephalosporins used for?
Less serious community-acquired infections
What are the major mechanisms of resistance against cephalosporins?
Beta-lactamases, Altered PBP binding site, Decreased drug penetration
What is the process involved in creating semi-synthetic cephalosporins?
Cleave off natural sidechain to yield 7-aminocephalosporanic acid (7-ACA) core, which then could be synthetically substituted with other sidechains.
Why are semi-synthetic cephalosporins important in medicine?
Alter the spectrum, stability, bioavailability, resistance to beta-lactamases.
